Stop loading of Contact Form 7 files on all blog posts unless there is a shortcode 'contact-form-7'

php

//Stop loading Contact From 7 CSS and Javascript on all pages.
	if( is_singular () ) {
    	$post = get_post ();
    	if( has_shortcode( $post -> post_content, 'contact-form-7' ) ) {
        	$check_cf7 = true;
    	}
    }
    if( !$check_cf7 ) {
        wp_dequeue_script( 'contact-form-7' );
        wp_dequeue_style ( 'contact-form-7' );
    }